The answer about removing them while in the water {when they are still
'soft'} was probably the best . . . for the bodies & large growth.

However, 'wet' or 'dry' you still have a potential problem {depending on
YOUR sensibilities}.The barnacle attaches it self with a secretion that
hardens into something that seems as hard as epoxy. Even when the animal
itself is scraped off, this 'ring' or 'button' remains.

I'd try a good 'Pressure Washing'. NOT the 'top of the line' pressure - THAT
can etch concrete. After the hull is washed & dried {although you will still
see the 'bases', you should be able to either apply colored bottom paint
{more for cosmetic / slime reasons in fresh water}or some sort of anti-slime
wax product.

However, IF you can't stand the look or 'feel' of the barnacle 'residue' . .
.. try a light 'sandblasting' with a less aggressive media like Walnut
Shells. You'll then have to apply a few coats of an epoxy 'barrier coat'
{But then I do that anyway}before any 'finish' is applied.

Regards & Good Luck,
Ron Magen
Backyard Boatshop

"mgarvie" wrote in message
news:tLByf.732581$xm3.166090@attbi_s21...
Not long ago, I was in the hospital for 2 months and my small flats boat
was
parked in brackish water the whole time in south Florida. Since then I've
moved to Illinois bringing the boat and the bottom COVERED with barnacles.
Can anyone give a clue on what I can get locally to remove them from a
fiberglass hull. Marine stores are non-existant here and I'm not sure if
a
boat repair shop would have any experience with barnacles in central
Illinois.

Thanls